1. Field of the Invention
This invention relates to a fusible link unit directly connected with a battery for vehicles without a cable.
2. Description of the Related Art
A conventional fusible link is shown in Japanese Patent Application Laid-Open Publication No. 2004-186006.
FIG. 1 shows a bus bar of the conventional fusible link disclosed in the above reference.
This fusible link comprises a flat plate-like bus bar 11 of an electrically conductive nature, and the pair of insulating housing (not shown). The bus bar 11 has fuse circuit-forming members 13A and 13B (which form large-current fuse circuit) integrally formed respectively at opposite sides of a band plate portion (bending portion) 12 formed generally at a central portion of the bus bar 11. The housings are formed integrally respectively on the pair of fuse circuit-forming members 13A, 13B by insert molding a synthetic resin. The band plate portion 12 is bent in such a manner that the pair of housings is disposed in parallel and opposed to each other, thereby forming the fusible link.
Tow pair of grooves 12a are formed at a generally central portion the base plate portion 12 by pressing, and extend in an upward-downward direction, the two pair of grooves 12a being spaced a predetermined distance from each other. The base plate portion 12 can be easily bent inwardly along the pair of grooves 12a. An alternator terminal portion 19 is form by bending and is located at the generally central portion of the base plate portion 12.
The fuse circuit-forming member 13A includes the elongate and narrow interconnecting plate portion 14 of a rectangular shape extending from one side edge of the band plate portion 12 at an upper end portion thereof, a plurality of screw-fastening terminal portions 16 which are connected to this interconnecting plate portion 14 in a chain-like manner through respective fuse elements (fusible portions) 15, and extend in a transverse direction, one battery terminal portion 17 which is connected directly (that is, not through the fusible portion) to one end of the interconnecting plate portion 14 remote from the band plate portion 12, and extends in the transverse direction, and fusible portion 18 (for an alternator circuit) which is formed at the other end portion of the interconnecting plate portion 14, and extends in the longitudinal direction.
The other fuse circuit-forming member 13B includes the elongate and narrow interconnecting plate portion 14 of a rectangular shape extending from the other side edge of the band plate portion 12 at the upper end portion thereof, and a plurality of screw-fastening terminal portion 16 which are connected to this interconnecting plate portion 14 in a chain-like manner through respective fuse elements 15. These fuse elements 15, 18 are blown when an electric current over a predetermined value flows therein.
The housings, which are formed integrally respectively on the pair of fuse circuit-forming members 13A, 13B by insert molding a synthetic resin, cover the whole of the fuse circuit-forming member 13A, 13B except of the band plate portion 12, fuse elements 15, 18, periphery of screw-fastening holes 16a, 17a, 17b of the terminal portions 16, 17.
According to the fusible link unit described above, the fuse circuit-forming members 13A, 13B are bent from both side ends in the same direction so that the fuse circuit-forming members 13A, 13B will be disposed in parallel with a predetermined distance. However, when the fuse circuit-forming members 13A, 13B are bent, the band plate portion itself comes to unexpectedly warp outwardly Consequently, distance between the fuse circuit-forming members 13A, 13B does not become constant, and then quality of the fusible link unit comes to degenerate.
According to the fusible link unit disclosed in the same references the groove 12a is formed by pressing on a predefined line along which the fuse circuit-forming members 13A, 13B. However, a cross section of the pressed area of the groove will decrease, and thus this decrease is disadvantage in view of a current-carrying capacity.